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1.
Urology ; 182: 161-167, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37689247

ABSTRACT

OBJECTIVE: To understand the relationship between common urologic medications phosphodiesterase-5 inhibitors (PDE5i) and anticholinergics (AC) and risk of dementia onset in men who underwent different primary treatments for prostate cancer. MATERIALS AND METHODS: Patients (>50years) with prostate cancer (1998-2022) without Alzheimer's disease or related dementias were selected from Cancer of the Prostatic Strategic Urologic Research Endeavor Registry. Minimum medication use was 3months. Fine-Gray regression was performed to determine the association between medication exposure and dementia onset ≥12months after primary treatment in men matched on age, race, comorbid conditions, smoking, and type of clinical site, with competing risk of death. RESULTS: Among 5937 men (53% PDE5i; 14% AC), PDE5i users were younger (63 vs 70, P < .01) with less CAD, CVA, DM (all P < .01); AC users were older (68 vs 66, P < .01) with higher incidence of comorbidities (P < .01). Median months of use was 24.3 (IQR 12.1, 48.7) for PDE5i and 12.2 (IQR 6.1, 24.3) for AC users. Cumulative incidence of Alzheimer's disease or related dementias was 6.5% at 15years. PDE5i (P = .07) and AC (P = .06) were not associated with dementia regardless of primary treatment modality. CONCLUSION: In this retrospective cohort study, PDE5i and AC use do not appear independently associated with risk of dementia. Notably, our cohort was generally healthy and younger which may limit our ability to detect significance. We recommend prospective investigation into association between PDE5i and dementia and advise continued judicious stewardship of AC in older patient populations.


Subject(s)
Alzheimer Disease , Prostatic Neoplasms , Male , Humans , Aged , Alzheimer Disease/complications , Alzheimer Disease/epidemiology , Alzheimer Disease/chemically induced , Retrospective Studies , Prospective Studies , Prostatic Neoplasms/complications , Prostatic Neoplasms/drug therapy , Prostate , Phosphodiesterase 5 Inhibitors/therapeutic use
2.
Urology ; 180: 242-248, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37442296

ABSTRACT

OBJECTIVE: To characterize the incidence of stress urinary incontinence (SUI) after radical prostatectomy (RP), its treatment, and impact on quality of life (QoL) and work status 1year after RP. MATERIALS AND METHODS: Prostate cancer patients treated by RP (1998-2016) were selected from CaPSURE. SUI was defined as any pads per day (ppd) 1 year after RP. SUI procedures were tracked by CPT codes (sling and artificial sphincter). Patients reported work status (full-time, part-time, unpaid), UCLA PCa Index urinary function (UF) and bother (UB) and SF36 Index physical function (PF). Associations of incontinence with UF, UB, and PF and work status changes were assessed (ANOVA). Lifetable estimates and Cox proportional hazards regression evaluated risk of undergoing SUI procedures. RESULTS: 664/2989 (22%) men treated with RP reported SUI at 1 year. More men with SUI had ≥GG2, intermediate to high-risk disease and non-nerve-sparing surgery (all P < .01). Cumulative incidence of SUI procedures was 1.4% at 10years after RP. Age (HR 2.68 per 10years, 95% CI 1.41-5.08) and number of ppd at 1 year (HR 3.20, 95% CI 2.27-4.50) were associated with undergoing SUI procedures. UF declined at 1year after RP, while UB and PF remained stable. UF, UB, and PF were inversely associated with number of ppd (all P < .01). Change in work status was not associated with incontinence or QoL scores. CONCLUSION: Incontinence affected QoL without impacting work status, suggesting that men with SUI after RP may continue working and go under-treated despite impact on QoL.

3.
PLoS One ; 14(6): e0215739, 2019.
Article in English | MEDLINE | ID: mdl-31166977

ABSTRACT

INTRODUCTION: Chronic nonbacterial osteomyelitis (CNO) is a rare autoinflammatory bone disorder primarily affecting children and adolescents. It can lead to chronic pain, bony deformities and fractures. The pathophysiology of CNO is incompletely understood. Scientific evidence suggests dysregulated expression of pro- and anti-inflammatory cytokines to be centrally involved. Currently, treatment is largely based on retrospective observational studies and expert opinion. Treatment usually includes nonsteroidal anti-inflammatory drugs and/or glucocorticoids, followed by a range of drugs in unresponsive cases. While randomised clinical trials are lacking, retrospective and prospective non-controlled studies suggest effectiveness of TNF inhibitors and bisphosphonates. The objective of the Bayesian consensus meeting was to quantify prior expert opinion. METHODS: Twelve international CNO experts were randomly chosen to be invited to a Bayesian prior elicitation meeting. RESULTS: Results showed that a typical new patient treated with pamidronate would have an 84% chance of improvement in their pain score relative to baseline at 26 weeks and an 83% chance on adalimumab. Experts thought there was a 50% chance that a new typical patient would record a pain score of 28mm (pamidronate) to 30mm (adalimumab) or better at 26 weeks. There was a modest trend in prior opinion to indicate an advantage of pamidronate vs adalimumab, with a 68% prior chance that pamidronate is superior to adalimumab by some margin. However, it is clear that there is considerable uncertainty about the precise relative merits of the two treatments. CONCLUSIONS: The rarity of CNO leads to challenges in conducting randomised controlled trials with sufficient power to provide a definitive outcome. We address this using a Bayesian design, and here describe the process and outcome of the elicitation exercise to establish expert prior opinion. This opinion will be tested in the planned prospective CNO study. The process for establishing expert consensus opinion in CNO will be helpful for developing studies in other rare paediatric diseases.


Subject(s)
Adalimumab/therapeutic use , Osteomyelitis/drug therapy , Pamidronate/therapeutic use , Bayes Theorem , Consensus , Female , Humans , Male , Osteomyelitis/complications , Pain Management , Randomized Controlled Trials as Topic , Research Design
4.
J Pediatr Urol ; 15(3): 224.e1-224.e6, 2019 May.
Article in English | MEDLINE | ID: mdl-30967356

ABSTRACT

INTRODUCTION: Little is known about long-term patient-reported outcomes following surgical repair for pediatric blunt urethral trauma. OBJECTIVE: The purpose was to evaluate long-term urinary outcomes, sexual function, and quality of life (QOL) of patients who undergo urethroplasty for blunt urethral trauma in childhood. STUDY DESIGN: After IRB approval, we retrospectively reviewed the records of patients who sustained blunt urethral injury at ≤18 years and underwent urethroplasty at our institution between 1978 and 2013. We then used a web-based survey to assess urinary/sexual/ejaculatory function and overall QOL using validated questionnaires. RESULTS: Of 68 eligible patients, 15 were able to be contacted (table). Median age of injury, age at urethroplasty, and age at follow-up were 17 (4-18), 17 (5-20), and 19 (13.5-21.5) years, respectively. The stricture was membranoprostatic in eight and bulbar in seven patients, with median length of 2 (1.6-2.6) cm. Excision/primary anastomosis was performed in all but three patients who required a buccal graft. Overall, 80% were 'very satisfied' and 20% were 'satisfied' with surgery. One patient reported a subsequent urethral intervention. On urethral stricture surgery patient-reported outcome measurement, the median bother (0 least, 24 worst) was 10 (8-12.5). The force of urine stream (1 strongest, 4 weakest) was 2 (1.5-2), with no report of urinary incontinence. The median Sexual Health Inventory for Men score (0 worst, 25 perfect) was 24 (22.5-24). The median ejaculatory function score (0 worst, 15 normal) was 14 (13-14.75). Six patients had fathered children and none reported infertility. Three patients reported <30° penile curvature not interfering with sex. Median QOL (0 worse, 10 best) was 8 (7.5-8). CONCLUSIONS: Urethroplasty after blunt urethral injury in young adult population is associated with a high long-term success rate with a low rate of long-term urinary and sexual consequences in adulthood.


Subject(s)
Forecasting , Plastic Surgery Procedures/methods , Quality of Life , Urethra/injuries , Urethral Stricture/surgery , Urination/physiology , Wounds and Injuries/complications , Adolescent , Child , Child, Preschool , Follow-Up Studies , Humans , Male , Patient Reported Outcome Measures , Retrospective Studies , Urethra/surgery , Urethral Stricture/etiology , Urethral Stricture/physiopathology , Urologic Surgical Procedures, Male , Wounds and Injuries/surgery , Young Adult
5.
Pharm Stat ; 17(5): 593-606, 2018 09.
Article in English | MEDLINE | ID: mdl-29984474

ABSTRACT

This paper provides an overview of "Improving Design, Evaluation and Analysis of early drug development Studies" (IDEAS), a European Commission-funded network bringing together leading academic institutions and small- to large-sized pharmaceutical companies to train a cohort of graduate-level medical statisticians. The network is composed of a diverse mix of public and private sector partners spread across Europe, which will host 14 early-stage researchers for 36 months. IDEAS training activities are composed of a well-rounded mixture of specialist methodological components and generic transferable skills. Particular attention is paid to fostering collaborations between researchers and supervisors, which span academia and the private sector. Within this paper, we review existing medical statistics programmes (MSc and PhD) and highlight the training they provide on skills relevant to drug development. Motivated by this review and our experiences with the IDEAS project, we propose a concept for a joint, harmonised European PhD programme to train statisticians in quantitative methods for drug development.


Subject(s)
Drug Development/education , Education, Graduate/methods , Statistics as Topic/education , Cooperative Behavior , Curriculum , Drug Development/statistics & numerical data , Drug Industry/organization & administration , Europe , Humans , Private Sector , Public Sector , Research/organization & administration
6.
Clin Pharmacol Ther ; 100(6): 699-712, 2016 12.
Article in English | MEDLINE | ID: mdl-27650716

ABSTRACT

A central question in the assessment of benefit/harm of new treatments is: how does the average outcome on the new treatment (the factual) compare to the average outcome had patients received no treatment or a different treatment known to be effective (the counterfactual)? Randomized controlled trials (RCTs) are the standard for comparing the factual with the counterfactual. Recent developments necessitate and enable a new way of determining the counterfactual for some new medicines. For select situations, we propose a new framework for evidence generation, which we call "threshold-crossing." This framework leverages the wealth of information that is becoming available from completed RCTs and from real world data sources. Relying on formalized procedures, information gleaned from these data is used to estimate the counterfactual, enabling efficacy assessment of new drugs. We propose future (research) activities to enable "threshold-crossing" for carefully selected products and indications in which RCTs are not feasible.


Subject(s)
Pharmaceutical Preparations/administration & dosage , Randomized Controlled Trials as Topic/methods , Research Design , Humans , Models, Theoretical , Treatment Outcome
7.
Br J Cancer ; 104(2): 324-31, 2011 Jan 18.
Article in English | MEDLINE | ID: mdl-21139582

ABSTRACT

BACKGROUND: Guanidine exchange factor (GEF)-catalysed activation of Rho proteins such as Cdc42 has been shown to have a crucial role in cellular transformation, malignant progression and invasion. We have previously shown that the HPV16 E6 oncoprotein binds to the PDZ domain protein Tax-interacting-protein 1 (Tip-1) and we now report identification and functional analysis of a novel Tip-1 binding GEF. METHODS: Yeast two-hybrid, in vitro pull-down, site-directed mutagenesis, semiquantitative PCR, co-immunoprecipitation and western blotting were used to identify/confirm novel Tip-1 binding partners and analyse cellular expression levels. In vitro kinetic analyses of recombinant proteins, siRNA gene silencing and in cell assays were used to measure Rho protein activation. RESULTS: Tax-interacting-protein 1 was shown to interact with ARHGEF16 by its carboxyl PDZ binding motif. Levels of ARHGEF16 were increased in transformed and immortalised cells expressing ectopic HPV16 E6 and Cdc42 was co-immunoprecipitated by ARHGEF16 in the presence of high-risk HPV E6. In vitro kinetic analysis confirmed that recombinant ARHGEF16 activates Cdc42 and this was increased by the addition of recombinant Tip-1 and E6. Cells expressing HPV16 E6 had higher levels of Cdc42 activation, which was decreased by siRNA silencing of either Tip-1 or ARHGEF16. CONCLUSION: These data suggest that HPV16 E6, Tip-1 and ARHGEF16 may cooperate to activate Cdc42 and support a potential link between the expression of HPV16 E6 and Cdc42 activation.


Subject(s)
Guanine Nucleotide Exchange Factors/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Oncogene Proteins, Viral/metabolism , Repressor Proteins/metabolism , cdc42 GTP-Binding Protein/metabolism , Base Sequence , Blotting, Western , DNA Primers , Gene Silencing , Mutagenesis, Site-Directed , Polymerase Chain Reaction , Protein Binding , RNA, Small Interfering , Reverse Transcriptase Polymerase Chain Reaction , Two-Hybrid System Techniques
8.
Int J Pediatr Otorhinolaryngol ; 74(1): 7-14, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19800138

ABSTRACT

OBJECTIVE: Human Papillomavirus (HPV) 6 and 11 are the aetiological agents responsible for Recurrent Respiratory Papillomatosis (RRP). There is general consensus that HPV11 results in more aggressive disease compared to HPV6. METHOD: Pubmed was searched using the terms respiratory papillomatosis, HPV 6 and HPV11. Comparisons were made in the outcomes of HPV6 versus HPV11 positive RRP disease. RESULTS: There are numerous sub-types or variants of both HPV6 and HPV11. These sub-types have different activities at least in-vitro. The numbers of different HPV types within RRP tissue may be more extensive than initially appeared. This depends specifically upon the HPV types tested for. CONCLUSION: The clinical differences between HPV6 and HPV11 disease may not be accurately predictable as these viruses exist in numerous sub-types. Also, RRP tissue may contain more than one subtype or even be co-infected with other viruses that may influence outcome. In-vitro studies upon cell lines are a reasonable starting point for evaluation of these differences.


Subject(s)
Human papillomavirus 11/isolation & purification , Human papillomavirus 6/isolation & purification , Papilloma/virology , Respiratory Tract Infections/virology , Condylomata Acuminata/epidemiology , Condylomata Acuminata/virology , Genome , Human papillomavirus 11/genetics , Human papillomavirus 6/genetics , Humans , Laryngostenosis/surgery , Oncogenic Viruses/genetics , Otorhinolaryngologic Surgical Procedures/statistics & numerical data , Papilloma/epidemiology , Papilloma/surgery , Recurrence , Severity of Illness Index , Tracheostomy/statistics & numerical data
9.
Br J Cancer ; 101(5): 829-39, 2009 Sep 01.
Article in English | MEDLINE | ID: mdl-19707205

ABSTRACT

BACKGROUND: Constitutive activation of RhoA-dependent RhoA kinase (ROCK) signalling is known to promote cellular transformation and the ROCK inhibitor Y-27632 has the ability to suppress focus formation of RhoA transformed NIH3T3 cells. METHODS: Sixty-four novel structural analogues of Y27632 were synthesised and tested for their ability to persistently inhibit the transformation of NIH3T3 cells by Rho guanidine exchange factor 16 (ARHGEF16) or Ras. In vitro kinase inhibitor profiling, co-culture of transformed cells with non-transformed cells and a novel Lucifer yellow/PKH67 dye transfer method were used to investigate their mode of action. RESULTS: Four Y27632 analogues inhibited transformed focus formation that persisted when the compound was withdrawn. No toxicity was observed against either transformed or non-transformed cells and the effect was dependent on co-culture of these two cell types. In vitro kinase inhibitor profiling indicated that these compounds had reduced activity against ROCK compared with Y27632, targeting instead Aurora A (AURKA), p38 (MAPK14) and Hgk (MAP4K4). Dye transfer analysis showed they increased gap junction intercellular communication (GJIC) between transformed and non-transformed cells. CONCLUSIONS: These data are the first to suggest that transient blockade of specific kinases can induce a persistent inhibition of non-contact inhibited transformed colony formation and can also remove pre-formed colonies. These effects could potentially be mediated by the observed increase in GJIC between transformed and non-transformed cells. Selection of kinase inhibitors with this property may thus provide a novel strategy for cancer chemoprevention.


Subject(s)
Amides/pharmacology , Cell Communication/drug effects , Cell Transformation, Neoplastic/drug effects , Gap Junctions/drug effects , Gap Junctions/metabolism , Guanine Nucleotide Exchange Factors/metabolism , Pyridines/pharmacology , Amides/chemical synthesis , Amides/chemistry , Animals , Aurora Kinase A , Aurora Kinases , Cell Line, Transformed , Cell Proliferation/drug effects , Cell Transformation, Neoplastic/metabolism , Cloning, Molecular/drug effects , Guanine Nucleotide Exchange Factors/antagonists & inhibitors , Guanine Nucleotide Exchange Factors/genetics , Mice , NIH 3T3 Cells , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein Serine-Threonine Kinases/metabolism , Pyridines/chemical synthesis , Pyridines/chemistry , RNA, Messenger/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/metabolism , rho-Associated Kinases/antagonists & inhibitors , rho-Associated Kinases/metabolism , NF-kappaB-Inducing Kinase
10.
Diabetologia ; 50(8): 1743-51, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17579833

ABSTRACT

AIMS/HYPOTHESIS: Intraportal infusion of serotonin (5-hydroxytryptamine, 5-HT) or inhibitors of its cellular uptake stimulate hepatic glucose uptake in vivo by either direct or indirect mechanisms. The aims of this study were to determine the direct effects of 5-HT in hepatocytes and to test the hypothesis that atypical antipsychotic drugs that predispose to type 2 diabetes counter-regulate the effects of 5-HT. MATERIALS AND METHODS: Rat hepatocytes were studied in short-term primary culture. RESULTS: Serotonin (5-HT) stimulated glycogen synthesis at nanomolar concentrations but inhibited it at micromolar concentrations. The stimulatory effect was mimicked by alpha-methyl-5-HT, a mixed 5-HT1/5-HT2 receptor agonist, whereas the inhibition was counteracted by a 5-HT2B/2C receptor antagonist. alpha-Methyl-5-HT stimulated glycogen synthesis additively with insulin, but unlike insulin, did not stimulate glucose phosphorylation and glycolysis, nor did it cause Akt (protein kinase B) phosphorylation. Stimulation of glycogen synthesis by alpha-methyl-5-HT correlated with depletion of phosphorylase a. This effect could not be explained by elevated levels of glucose 6-phosphate, which causes inactivation of phosphorylase, but was explained, at least in part, by decreased phosphorylase kinase activity in situ. The antipsychotic drugs clozapine and olanzapine, which bind to 5-HT receptors, counteracted the effect of alpha-methyl-5-HT on phosphorylase inactivation. CONCLUSIONS/INTERPRETATION: This study provides evidence for both stimulation and inhibition of glycogen synthesis in hepatocytes by serotonergic mechanisms. The former effects are associated with the inactivation of phosphorylase and are counteracted by atypical antipsychotic drugs that cause hepatic insulin resistance. Antagonism of hepatic serotonergic mechanisms may be a component of the hepatic dysregulation caused by antipsychotic drugs that predispose to type 2 diabetes.


Subject(s)
Antipsychotic Agents/pharmacology , Glycogen/biosynthesis , Hepatocytes/drug effects , Phosphorylases/metabolism , Serotonin/metabolism , Amides/pharmacology , Animals , Benzodiazepines/pharmacology , Blotting, Western , Cells, Cultured , Clozapine/pharmacology , Diabetes Mellitus, Type 2/metabolism , Enzyme Activation/drug effects , Hepatocytes/cytology , Hepatocytes/metabolism , Immunoblotting , Indoles/pharmacology , Male , Olanzapine , Phosphorylases/antagonists & inhibitors , Rats , Rats, Wistar , Serotonin/pharmacology , Serotonin 5-HT1 Receptor Agonists , Serotonin 5-HT2 Receptor Agonists , Serotonin 5-HT2 Receptor Antagonists
11.
Diabetologia ; 49(1): 174-82, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16341839

ABSTRACT

AIMS/HYPOTHESIS: An insulin signalling pathway leading from activation of protein kinase B (PKB, also known as Akt) to phosphorylation (inactivation) of glycogen synthase kinase-3 (GSK-3) and activation of glycogen synthase is well characterised. However, in hepatocytes, inactivation of GSK-3 is not the main mechanism by which insulin stimulates glycogen synthesis. We therefore tested whether activation of PKB causes inactivation of glycogen phosphorylase. MATERIALS AND METHODS: We used a conditionally active form of PKB, produced using recombinant adenovirus, to test the role of acute PKB activation in the control of glycogen phosphorylase and glycogen synthesis in hepatocytes. RESULTS: Conditional activation of PKB mimicked the inactivation of phosphorylase, the activation of glycogen synthase, and the stimulation of glycogen synthesis caused by insulin. In contrast, inhibition of GSK-3 caused activation of glycogen synthase but did not mimic the stimulation of glycogen synthesis by insulin. PKB activation and GSK-3 inhibition had additive effects on the activation of glycogen synthase, indicating convergent mechanisms downstream of PKB involving inactivation of either phosphorylase or GSK-3. Glycogen synthesis correlated inversely with the activity of phosphorylase-a, irrespective of whether this was modulated by insulin, by PKB activation or by a selective phosphorylase ligand, supporting an essential role for phosphorylase inactivation in the glycogenic action of insulin in hepatocytes. CONCLUSIONS/INTERPRETATION: In hepatocytes, the acute activation of PKB, but not the inhibition of GSK-3, mimics the stimulation of glycogen synthesis by insulin. This is explained by a pathway downstream of PKB leading to inactivation of phosphorylase, activation of glycogen synthase, and stimulation of glycogen synthesis, independent of the GSK-3 pathway.


Subject(s)
Hepatocytes/physiology , Insulin/pharmacology , Proto-Oncogene Proteins c-akt/physiology , Animals , Cells, Cultured , Enzyme Activation , Glycogen Synthase Kinase 3/metabolism , Hepatocytes/cytology , Hepatocytes/drug effects , Male , Phosphatidylinositol 3-Kinases/metabolism , Phosphorylation , Rats , Rats, Wistar
13.
J Biol Chem ; 276(26): 23858-66, 2001 Jun 29.
Article in English | MEDLINE | ID: mdl-11309391

ABSTRACT

We used metabolic control analysis to determine the flux control coefficient of phosphorylase on glycogen synthesis in hepatocytes by titration with a specific phosphorylase inhibitor (CP-91149) or by expression of muscle phosphorylase using recombinant adenovirus. The muscle isoform was used because it is catalytically active in the b-state. CP-91149 inactivated phosphorylase with sequential activation of glycogen synthase. It increased glycogen synthesis by 7-fold at 5 mm glucose and by 2-fold at 20 mm glucose with a decrease in the concentration of glucose causing half-maximal rate (S(0.5)) from 26 to 19 mm. Muscle phosphorylase was expressed in hepatocytes mainly in the b-state. Low levels of phosphorylase expression inhibited glycogen synthesis by 50%, with little further inhibition at higher enzyme expression, and caused inactivation of glycogen synthase that was reversed by CP-91149. At endogenous activity, phosphorylase has a very high (greater than unity) negative control coefficient on glycogen synthesis, regardless of whether it is determined by enzyme inactivation or overexpression. This high control is attenuated by glucokinase overexpression, indicating dependence on other enzymes with high control. The high control coefficient of phosphorylase on glycogen synthesis affirms that phosphorylase is a strong candidate target for controlling hyperglycemia in type 2 diabetes in both the absorptive and postabsorptive states.


Subject(s)
Hepatocytes/metabolism , Liver Glycogen/biosynthesis , Phosphorylases/metabolism , Adenosine Monophosphate/pharmacology , Adenoviridae/genetics , Amides/pharmacology , Animals , Cells, Cultured , Enzyme Inhibitors/pharmacology , Glucagon/pharmacology , Glucokinase/genetics , Glucokinase/metabolism , Glucose/pharmacology , Glycogen Synthase/genetics , Glycogen Synthase/metabolism , Hepatocytes/drug effects , Hepatocytes/enzymology , Indoles/pharmacology , Male , Phosphorylase b/antagonists & inhibitors , Phosphorylase b/metabolism , Phosphorylases/antagonists & inhibitors , Rats , Rats, Wistar , Transfection
14.
J Biol Chem ; 276(12): 9189-98, 2001 Mar 23.
Article in English | MEDLINE | ID: mdl-11106657

ABSTRACT

The difficulties associated with studying molecular mechanisms important in hemopoietic stem cell (HSC) function such as the problems of purifying homogeneous stem cell populations, have prompted us to adapt the murine ES cell system as an in vitro model of HSC generation and function. We now report that careful analysis of the time course of HSC generation in differentiating ES cells allows them to be used as a source of known and novel hemopoietic gene products. We have generated a subtracted library using cDNA from ES cells collected just prior to and just following the emergence of HSCs. Analysis of this library shows it to be a rich source of known hemopoietic and hemopoietic related gene products with 44% of identifiable cDNAs falling into these camps. We have demonstrated the value of this system as a source of novel genes of relevance to HSC function by characterizing a novel membrane protein encoding cDNA that is preferentially expressed in primitive hemopoietic cells. Intriguingly, further analysis of the known components of the subtracted library is suggestive of erythroid preconditioning of the ES cell-derived HSC. We have used dot-blot and in situ analysis to indicate that this erythroid preconditioning is probably restricted to primitive but not definitive HSC.


Subject(s)
Cell Differentiation , Embryo, Mammalian/cytology , Gene Expression Profiling , Stem Cells/cytology , Amino Acid Sequence , Animals , Base Sequence , Cell Line , DNA Primers , DNA, Complementary , Mice , Molecular Sequence Data , Sequence Homology, Amino Acid , Stem Cells/metabolism , Subtraction Technique
15.
Hematol J ; 2(3): 150-60, 2001.
Article in English | MEDLINE | ID: mdl-11920240

ABSTRACT

INTRODUCTION: The serine protease inhibitor Serpin 2A is highly expressed in ex vivo bipotent granulocyte/macrophage progenitor cells and in cultured myeloid stem cells. The gene undergoes rapid down-regulation as these cells are induced to differentiate, and constitutive expression in cultured myeloid stem cells retards maturation. Serpin 2A is also expressed in T cells as a consequence of activation. We now report analysis of the upstream regulatory elements that control Serpin 2A transcription. MATERIALS AND METHODS: Using primer extension and rapid amplification of cDNA ends the transcription start site of the Serpin 2A gene was mapped, and a 1.2 Kb genomic upstream fragment cloned and sequenced. Promoter activity and protein binding of deletion and site-directed mutant constructs were analysed by transient transfection and by electrophoretic mobility shift assays. RESULTS: A minimal promoter fragment was identified with high activity dependent on NF-kappa and Moloney murine leukaemia enhancer factor LVa binding sites in both myeloid stem cells and activated T cells. NF-kappa was shown to be the main DNA binding protein in T cells, whereas that in haematopoietic stem cells appears to be novel. CONCLUSION: Serpin 2A promoter activity in T cells is due predominantly to NF-kappa binding to its consensus site. Activity in haematopoietic stem cells appears to be mediated by a novel protein, which recognises the NF-kappa consensus only in the context of flanking sequences. This concise regulatory element may be of potential value in gene therapeutic applications.


Subject(s)
Gene Expression Regulation , Hematopoietic Stem Cells/metabolism , Lymphocyte Activation/genetics , Promoter Regions, Genetic , Serpins/genetics , T-Lymphocytes/metabolism , Animals , Base Sequence , Binding Sites , Cells, Cultured , Chromosome Mapping , Consensus Sequence , Cosmids , DNA-Binding Proteins/metabolism , Electrophoretic Mobility Shift Assay , Exons/genetics , Genes, Reporter , Mice , Mice, Inbred BALB C , Mice, Inbred CBA , Molecular Sequence Data , Mutagenesis, Site-Directed , NF-kappa B/metabolism , Organ Specificity , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sequence Deletion , Serpins/biosynthesis , T-Lymphocytes/immunology , Transcription, Genetic , Transfection
16.
Br J Haematol ; 110(3): 674-81, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10997980

ABSTRACT

This work aimed to provide a means of assaying directly the effects of transient expression of introduced genes on the survival, proliferation, lineage commitment and differentiation of haemopoietic progenitor cells. For this purpose, we have developed a system that allows isolation of productively transfected, mulitipotent haemopoietic cells within a few hours of the introduction of test genes. We have shown that FDCP-mix cells productively transfected with expression plasmids encoding green fluorescent protein (GFP) differentiate normally and retain colony-forming potential. We constructed an expression vector consisting of a bicistronic cassette in which a GFP marker gene and a test gene are driven from the same promoter. The vector design has been optimized for co-expression and the test gene was shown to be biologically active. The expression profile from a transiently transfected template under different growth conditions reveals that active expression continues for at least 2 d after transfection. The transient transfection of FDCP-mix cells with the vectors described provides a powerful tool for analysis of the immediate early effects of test gene overexpression during haemopoietic differentiation.


Subject(s)
Genes, Regulator , Hematopoietic Stem Cells/metabolism , Animals , Cell Culture Techniques , Cell Differentiation/genetics , Cell Line , Cell Survival/genetics , Colony-Forming Units Assay , Electroporation , Gene Expression , Genetic Vectors/genetics , Green Fluorescent Proteins , Humans , Luminescent Proteins/genetics , Mice , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/analysis
17.
FASEB J ; 14(1): 55-64, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10627280

ABSTRACT

CD105 (endoglin), a receptor for transforming growth factor beta (TGFbeta), is highly expressed in tissue-cultured, activated endothelial cells in vitro and in tissues undergoing angiogenesis in vivo. The absence of CD105 in knockout mice leads to their death from defective vascular development, but the role of CD105 in the modulation of angiogenesis has not been elucidated. TGFbeta1 is a well-recognized regulator of angiogenesis. Using an antisense approach, we have shown that inhibition of CD105 protein translation in cultured human endothelial cells enhances the ability of TGFbeta1 to suppress growth and migration in these cells. The ability of endothelial cells to form capillary tubes was evaluated by the use of a 3-dimensional collagen matrix system where TGFbeta1 not only reduced the length of capillary-like structures, but also caused massive mortality in CD105-deficient cells compared to control cultures. These results provide direct evidence that CD105 antagonizes the inhibitory effects of TGFbeta1 on human vascular endothelial cells and that normal cellular levels of CD105 are required for the formation of new blood vessels.


Subject(s)
Endothelium, Vascular/metabolism , Signal Transduction/physiology , Transforming Growth Factor beta/metabolism , Vascular Cell Adhesion Molecule-1/physiology , Animals , Antigens, CD , Base Sequence , Cell Death/drug effects , Cell Movement/drug effects , Cells, Cultured , DNA Primers , Endoglin , Endothelium, Vascular/cytology , Endothelium, Vascular/drug effects , Humans , Mice , Neovascularization, Physiologic/physiology , Oligonucleotides, Antisense/pharmacology , RNA, Messenger/metabolism , Receptors, Cell Surface , Transforming Growth Factor beta/pharmacology , Vascular Cell Adhesion Molecule-1/genetics
20.
Genes Dev ; 13(22): 3027-33, 1999 Nov 15.
Article in English | MEDLINE | ID: mdl-10580009

ABSTRACT

The p16(INK4a) tumor suppressor inhibits cyclin-dependent kinases (CDK4 and CDK6). Here we report the isolation of a novel gene, SEI-1, whose product (p34(SEI-1)) appears to antagonize the function of p16(INK4a). Addition of p34(SEI-1) to cyclin D1-CDK4 renders the complex resistant to inhibition by p16(INK4a). Expression of SEI-1 is rapidly induced on addition of serum to quiescent fibroblasts, and ectopic expression of p34(SEI-1) enables fibroblasts to proliferate even in low serum concentrations. p34(SEI-1) seems to act as a growth factor sensor and may facilitate the formation and activation of cyclin D-CDK complexes in the face of inhibitory levels of INK4 proteins.


Subject(s)
Carrier Proteins/physiology , Cyclin-Dependent Kinases/metabolism , Nuclear Proteins , Proto-Oncogene Proteins , Trans-Activators , Animals , Blood Physiological Phenomena , COS Cells , Cell Cycle/physiology , Cells, Cultured , Chlorocebus aethiops , Chromosomes, Human, Pair 19/genetics , Culture Media, Serum-Free , Cyclin-Dependent Kinase 4 , Cyclin-Dependent Kinase Inhibitor p16/antagonists & inhibitors , DNA, Complementary/genetics , Enzyme Activation , Fibroblasts/drug effects , Fibroblasts/enzymology , Genes , HeLa Cells , Humans , Saccharomyces cerevisiae , Transcription Factors , Transfection , Two-Hybrid System Techniques
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